This credit\'s language in LEED-NC 2.2 specifies a formula that quantifies the environmental impact of various refrigerants. One of the parameters in that formula is the Refrigerant Leakage Rate, Lr. The allowed range of values is 0.5%/year to 2.0%/year, with a default assumption of 2% required unless the project team justifies a lower rate. In general, this requires project teams to submit further documentation to USGBC in their certification application as described in the LEED-NC 2.2 Reference Guide. The Trane Company has submitted manufacturer\'s data and recommended operation & maintenance practices to USGBC for its new low-pressure, R-123 CenTraVac model of centrifugal chiller (model numbers starting with CVHE, CVHF, CVHG, CDHF, or CDHG). This documentation meets the requirements listed in the LEED-NC 2.2 Reference Guide, and thus justifies using a leakage rate assumption of 0.5% in the LEED-NC 2.2 compliance formula. LEED-NC 2.2 projects using this type of chiller may use the 0.5% assumption by specifying this chiller and by citing this CIR; they need not provide further supporting documentation to USGBC in their certification application. USGBC encourages other HVAC equipment manufacturers to do similar studies and submit similar documentation to USGBC for consideration. Note: This ruling was rescinded on April 30th, 2009. All LEED-NCv2.2 projects registered previous to April 30th, 2009 may use the guidance in the CIR. All projects registered after April 30th must use default values for leakage rates. Applicable Internationally.